Caterpillar Offers New C12 Engine

Caterpillar recently released a full line of ratings for its new C12 marine diesel engine, the electronically controlled, compact, lightweight 12-liter diesel. With the signature Caterpillar four-stroke, in-line six-cylinder design, the engine is rated 345 mhp (340 bhp, 254 bkW) at 1,800 rpm to 710 mhp (700 bhp, 522 bkW) at 2,300 rpm. The C12 is aimed at small to mid-sized commercial vessel applications, and is available for worldwide distribution. At its 710 mhp rating, the manufacturer claims that the engine offers the best power-to-weight ratio in its class: 3.65 lb/mhp.

Something Old ... Something New The C12 borrows heavily from other engines in the Caterpillar stable, yet features a number of innovations unique to this unit, designed to enhance both performance and durability. For example, a new exhaust manifold design with a special casting at the entrance to the turbocharger reduces backpressure and improves exhaust gas flow, resulting in increased power and lower exhaust temperatures.

Piston ring position and cooling oil jet flow to the piston have been fine-tuned to reduce engine temperatures and are designed to improve power output. A new aftercooler core design is to reduce thermal and vibration stress to increase engine durability. In its three highest ratings configurations, the C12 uses the same high-efficiency turbocharger that has proven successful in a twin-turbo arrangement on the larger Cat 3412E. Electronic control for the engine is provided by Caterpillar's ADEM III electronic control module (ECM). ADEM III has nearly eight times as much memory, nearly twice the input/output capacity and significantly faster processing speed compared to previously available Cat ECMs. The C12s ECM control software is written to maximize power and performance at all commercial ratings, while reducing fuel consumption and meeting all known current and future requirements for NOx emissions. The new engine is also available in keel-cooled configurations to handle the most demanding workboat and fishing boat applications.